103 lines
3.2 KiB
Python
103 lines
3.2 KiB
Python
# Modify from https://github.com/liyunsheng13/dcd/blob/main/models/imagenet/mobilenetv2_dcd.py
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import torch
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import torch.nn as nn
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import torch.nn.functional as F
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class Hsigmoid(nn.Module):
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def __init__(self, inplace=True):
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super(Hsigmoid, self).__init__()
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self.inplace = inplace
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def forward(self, x):
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return F.relu6(x + 3., inplace=self.inplace) / 3.
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class DYModule(nn.Module):
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def __init__(self, inp, oup, fc_squeeze=8):
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super(DYModule, self).__init__()
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self.conv = nn.Conv2d(inp, oup, 1, 1, 0, bias=False)
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if inp < oup:
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self.mul = 4
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reduction = 8
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self.avg_pool = nn.AdaptiveAvgPool2d(2)
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else:
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self.mul = 1
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reduction = 2
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self.avg_pool = nn.AdaptiveAvgPool2d(1)
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self.dim = min((inp * self.mul) // reduction, oup // reduction)
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while self.dim ** 2 > inp * self.mul * 2:
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reduction *= 2
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self.dim = min((inp * self.mul) // reduction, oup // reduction)
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if self.dim < 4:
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self.dim = 4
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squeeze = max(inp * self.mul, self.dim ** 2) // fc_squeeze
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if squeeze < 4:
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squeeze = 4
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self.conv_q = nn.Conv2d(inp, self.dim, 1, 1, 0, bias=False)
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self.fc = nn.Sequential(
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nn.Linear(inp * self.mul, squeeze, bias=False),
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SEModule_small(squeeze),
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)
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self.fc_phi = nn.Linear(squeeze, self.dim ** 2, bias=False)
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self.fc_scale = nn.Linear(squeeze, oup, bias=False)
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self.hs = Hsigmoid()
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self.conv_p = nn.Conv2d(self.dim, oup, 1, 1, 0, bias=False)
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# self.bn1 = nn.BatchNorm2d(self.dim)
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self.bn1 = nn.GroupNorm(num_groups=4, num_channels=self.dim)
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# self.bn2 = nn.BatchNorm1d(self.dim)
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self.bn2 = nn.GroupNorm(num_groups=4, num_channels=self.dim)
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def forward(self, x):
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r = self.conv(x)
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b, c, h, w = x.size()
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y = self.avg_pool(x).view(b, c * self.mul)
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y = self.fc(y)
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dy_phi = self.fc_phi(y).view(b, self.dim, self.dim)
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dy_scale = self.hs(self.fc_scale(y)).view(b, -1, 1, 1)
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r = dy_scale.expand_as(r) * r
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x = self.conv_q(x)
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x = self.bn1(x)
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x = x.view(b, -1, h * w)
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x = self.bn2(torch.matmul(dy_phi, x)) + x
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x = x.view(b, -1, h, w)
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x = self.conv_p(x)
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return x + r
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class SEModule_small(nn.Module):
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def __init__(self, channel):
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super(SEModule_small, self).__init__()
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self.fc = nn.Sequential(
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nn.Linear(channel, channel, bias=False),
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Hsigmoid()
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)
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def forward(self, x):
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y = self.fc(x)
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return x * y
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class SEModule(nn.Module):
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def __init__(self, channel, reduction=4):
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super(SEModule, self).__init__()
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self.avg_pool = nn.AdaptiveAvgPool2d(1)
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self.fc = nn.Sequential(
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nn.Linear(channel, channel // reduction, bias=False),
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nn.ReLU(inplace=True),
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nn.Linear(channel // reduction, channel, bias=False),
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Hsigmoid()
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)
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def forward(self, x):
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b, c, _, _ = x.size()
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y = self.avg_pool(x).view(b, c)
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y = self.fc(y).view(b, c, 1, 1)
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return x * y.expand_as(x)
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